Production of fuel from co-processing multiple renewable feedstocks

ABSTRACT

A process for producing a fuel or fuel blending component from co-processing at least two different classes of renewable feedstocks, is presented. One feedstock comprises glycerides and free fatty acids in feedstocks such as plant and animal oils while the other feedstock comprises biomass derived pyrolysis oil. The source of the animal or plant oil and the biomass may be the same renewable source.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Provisional Application Ser. No.61/122,780 filed Dec. 16, 2008, the contents of which are herebyincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

The process produces at least one fuel from at least two different typesof renewable feedstocks including biomass derived pyrolysis oil and thetriglycerides and free fatty acids found in plant and animal oils fatsand greases. The two different types of renewable feedstocks areco-processed with at least one paraffin rich component produced from thetriglycerides and free fatty acids found in plant and animal oils fatsand greases and with at least one cyclic rich component produced from abiomass derived pyrolysis oil. The effluent containing at least oneparaffin rich fuel component and at least one aromatic rich fuelcomponent is useful as at least one fuel or fuel blending component. Thefuel, fuel additives, or blending components generated may include thosein the gasoline boiling point range, the diesel boiling point range, andor the aviation boiling point range.

As the demand for gasoline, diesel fuel, and aviation fuel increasesworldwide there is increasing interest in sources other than petroleumcrude oil for producing these fuels. One such source is what has beentermed renewable feedstocks. One type of renewable feedstocks include,but are not limited to, plant oils such as corn, rapeseed, canola,soybean and algal oils, animal fats such as inedible tallow, fish oilsand various waste streams such as yellow and brown greases and sewagesludge. The common feature of these feedstocks is that they are composedof glycerides and Free Fatty Acids (FFA). Both of these compoundscontain aliphatic carbon chains having from about 8 to about 24 carbonatoms. The aliphatic carbon chains in the triglycerides or FFAs can alsobe mono-, di- or poly-unsaturated. Some of the glycerides from therenewable sources may be monoglycerides or diglycerides instead of or inaddition to the trigylcerides. This type of feedstock is employed togenerate the paraffinic portion of a fuel.

There are reports in the art disclosing the production of hydrocarbonsfrom oils. For example, U.S. Pat. No. 4,300,009 discloses the use ofcrystalline aluminosilicate zeolites to convert plant oils such as cornoil to hydrocarbons such as gasoline and chemicals such as para-xylene.U.S. Pat. No. 4,992,605 discloses the production of hydrocarbon productsin the diesel boiling point range by hydroprocessing vegetable oils suchas canola or sunflower oil. Finally, US 2004/0230085 A1 discloses aprocess for treating a hydrocarbon component of biological origin byhydrodeoxygenation followed by isomerization.

The generation of the cyclic rich component of the fuel employs aprocess for obtaining a cyclic rich component from biomass. Moreparticularly, this process relates to the treatment of pyrolysis oilproduced from the pyrolysis of biomass to produce fuel or fuel blendingor additive components. As discussed above, renewable energy sources areof increasing importance. They are a means of reducing dependence onpetroleum oil and provide a substitute for fossil fuels. Also, renewableresources can provide for basic chemical constituents to be used inother industries, such as chemical monomers for the making of plastics.Biomass is a renewable resource that can provide some of the needs forsources of chemicals and fuels.

Biomass includes, but is not limited to, lignin, plant parts, fruits,vegetables, plant processing waste, wood chips, chaff, grain, grasses,corn, corn husks, weeds, aquatic plants, hay, paper, paper products,recycled paper and paper products, and any cellulose containingbiological material or material of biological origin. Lignocellulosicbiomass, or cellulosic biomass as used throughout the remainder of thisdocument, consists of the three principle biopolymers cellulose,hemicellulose, and lignin. The ratio of these three components variesdepending on the biomass source. Cellulosic biomass might also containlipids, ash, and protein in varying amounts. The economics forconverting biomass to fuels or chemicals depend on the ability toproduce large amounts of biomass on marginal land, or in a waterenvironment where there are few or no other significantly competingeconomic uses of that land or water environment. The economics can alsodepend on the disposal of biomass that would normally be placed in alandfill.

The growing, harvesting and processing of biomass in a water environmentprovides a space where there is plenty of sunlight and nutrients whilenot detracting from more productive alternate uses. Biomass is alsogenerated in many everyday processes as a waste product, such as wastematerial from crops. In addition, biomass contributes to the removal ofcarbon dioxide from the atmosphere as the biomass grows. The use ofbiomass can be one process for recycling atmospheric carbon whileproducing fuels and chemical precursors. Biomass when heated at shortcontact times in an environment with low or no oxygen, termed pyrolysis,will generate a liquid product known as pyrolysis oil. Synonyms forpyrolysis oil include bio-oil, pyrolysis liquids, bio-crude oil, woodliquids, wood oil, liquid smoke, wood distillates, pyroligneous acid,and liquid wood

The product of the biomass pyrolysis, the pyrolysis oil, contains whatis known as pyrolysis oil non-aqueous phase. Pyrolysis oil non-aqueousphase is the water insoluble portion of the pyrolysis oil. The pyrolysisoil may be processed whole, or a portion of the aqueous phase may beremoved to provide a pyrolysis oil enriched in pyrolysis oil non-aqueousphase which is co-processed along with the triglycerides throughdeoxygenation to produce the cyclic rich portion of the fuel or fuelblending component.

The process herein involves co-processing the pyrolysis oil feedstockand the triglyceride and FFA feedstock by hydrogenation, deoxygenation(decarboxylation, decarbonylation, and/or hydrodeoxygenation) in atleast a first zone and hydroisomerization and hydrocracking in at leasta second zone in order to generate a gasoline range product, a dieselrange product, and or an aviation range product. Simply hydrogenatingand deoxygenating the renewable glyceride or FFA feedstocks in ahydrogen environment in the presence of a hydrotreating catalyst resultsin straight chain paraffins having chain-lengths similar to, or slightlyshorter than, the fatty acid composition of the feedstock. With manyfeedstocks, this approach results in a fuel meeting the generalspecification for a diesel fuel, but not the specifications for anaviation fuel. The selective hydrocracking reaction reduces the carbonchain length to allow selectivity to aviation fuel range paraffins whileminimizing lower molecular weight products. Similarly, isomerizationincreases the concentration of branched paraffins and thereby improvecold flow properties such as cloud point or freeze point.

The pyrolysis oil and the triglycerides are co-processed to generate aneffluent comprising at least one paraffin rich component and at leastone cyclic rich component. The effluent is useful as a fuel or a fuelblending component. The relative amounts of the feedstocks may becontrolled so that the resulting effluent meets specific requirements ofa target fuel. Other additives or components may be blended with theeffluent in order to meet additional requirements of the target fuel.The target fuel may be in the boiling point ranges of gasoline,aviation, and diesel, and may be entirely derived from renewablesources. The target fuel is designed to power engines or devices thatare currently distributed around the world without requiring upgrades tothose engines. The target fuel may be blended with other componentsgenerated from renewable feedstocks to meet the specifications usingentirely renewable feedstock derived blending components, or the targetfuel may be blended with petroleum derived fuels or fuel blendingcomponents in any concentration.

SUMMARY OF THE INVENTION

A process for producing a fuel having both a paraffin rich component anda cyclic rich component where the paraffin rich component and the cyclicrich component are each produced from a renewable feedstock. Therenewable feedstocks are co-processed together. The paraffin richcomponent is produced from the triglycerides and free fatty acids foundin plant and animal oils, fats, and greases, and the cyclic richcomponent is produced from a biomass derived pyrolysis oil. The cyclicrich component has biomass derived pyrolysis oil as the renewablefeedstock. The pyrolysis oil is derived from the pyrolysis of biomass.The pyrolysis oil may optionally be enriched in pyrolysis oilnon-aqueous phase through the removal of at least a portion of theaqueous phase, but the process also allows the whole pyrolysis oil to beprocessed without removal of a portion of the aqueous phase. Thetriglycerides and free fatty acid feedstock and the biomass derivedpyrolysis oil feedstock are co-processed through the zones of theprocess.

Both types of feedstocks are simultaneously treated in a common reactionzone by hydrogenating and deoxygenating the feedstock mixture atreaction conditions to provide a first reaction zone product comprisingn-paraffins and cyclic hydrocarbons.

In one embodiment, the first reaction zone may have two stages, with thetriglycerides and free fatty acids along with the whole pyrolysis oil orthe pyrolysis oil non-aqueous phase enriched pyrolysis oil, all beingtreated in a first deoxygenation zone generating a partiallydeoxygenated stream. Water, gasses, and light ends are removed and theremainder of the partially deoxygenated stream is further treated in asecond deoxygenation zone to produce a deoxygenated product stream. Thedeoxygenated product stream comprises n-paraffins and cyclic hydrocarboncompounds that when fractionated are useful fuels in the gasoline andnaphtha/gasoline, aviation, and diesel boiling point ranges.

After the second deoxygenation zone, water light ends, and gasses may beremoved from the effluent of the second deoxygenation zone. Hydrogen maybe separated and recycled. In one embodiment the first and seconddeoxygenation zones are combined and housed within in a single reactor.

The carbon dioxide and water generated as byproducts in the firstreaction zone may be selectively removed from the first reaction productin an optional integrated hot high pressure stripper using hydrogen asthe stripping gas. A diesel range stream, an aviation range stream, anaphtha/gasoline range stream, a naphtha/gasoline and LPG range streamor any mixture thereof may be optionally used as a rectification agentin the selective hot high pressure hydrogen stripper to decrease theamount of first reaction zone diesel and aviation range product carriedin the overhead of the selective hot high pressure hydrogen stripper.Note that the naphtha/gasoline range stream is within the boiling pointrange for gasoline and therefore may also be considered a gasolineboiling point range stream.

The hydrogen stripped first reaction zone product may optionally beintroduced to a hydroisomerization and selective cracking reaction zone.The selective hydrocracking allows for aviation fuel range products, ifdesired, by preferentially cracking C1 to C6 fragments off the end ofthe longer chain paraffins and by minimizing the number of crackingevents per molecule. The selective cracking also breaks apart thestronger carbon-oxygen linkages that remain from the pyrolysis oil typeof feedstock. The desired product, at least one paraffin rich componentin the diesel boiling point range, the aviation boiling point range, andor the naphthene boiling range product, is recovered.

The effluent comprising at least one paraffin rich component and atleast one cyclic rich component form at least one fuel or may be blendedwith other components to form additional fuels.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic of one embodiment a process. FIG. 1 shows theoption where the combined feedstocks of whole pyrolysis oil andtriglyceride and free fatty acids is processed through a single stage ofdeoxygenation.

FIG. 2 is a schematic of one embodiment of a process. FIG. 2 shows theoption where the combined feedstocks of whole pyrolysis oil andtriglyceride and free fatty acids is processed through two stages ofdeoxygenation.

FIG. 3 is a schematic of one embodiment of a process. FIG. 3 shows theoption where the pyrolysis oil feedstock is phase separated with thepyrolysis oil non-aqueous phase being combined with a triglyceride andfree fatty acids feedstock to be co-processed through two stages ofdeoxygenation.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides a process for generating a fuel or fuel blendingcomponent from a renewable feedstock comprising at least glycerides anda second renewable feedstock comprising at least a portion of apyrolysis oil, where the two renewable feedstocks are co-processedtogether to provide the fuel or fuel blending component. The fuel may beone of several types of hydrocarbon mixtures, a diesel boiling pointrange hydrocarbon mixture, an aviation boiling point range hydrocarbonmixture, and/or a naphtha/gasoline boiling point range mixture.

The term renewable feedstock is meant to include feedstocks other thanthose obtained from petroleum crude oil. Another term that has been usedto describe members of this class of feedstock is biorenewable fats andoils. The first class of renewable feedstocks that can be used togenerate a paraffin rich portion of the fuel include any of those whichcomprise glycerides and free fatty acids (FFA). Most of the glycerideswill be triglycerides, but monoglycerides and diglycerides may bepresent and processed as well. Examples of these renewable feedstocksinclude, but are not limited to, canola oil, corn oil, soy oils,rapeseed oil, soybean oil, colza oil, tall oil, sunflower oil, hempseedoil, olive oil, linseed oil, coconut oil, castor oil, peanut oil, palmoil, mustard oil, cottonseed oil, jatropha oil, inedible tallow, yellowand brown greases, lard, train oil, fats in milk, fish oil, algal oil,sewage sludge, cuphea oil, camelina oil, jatropha oil, curcas oil,babassu oil, palm kernel oil, and the like. The glycerides and FFAs ofthe typical vegetable or animal fat contain aliphatic hydrocarbon chainsin their structure which have about 8 to about 24 carbon atoms with amajority of the fats and oils containing high concentrations of fattyacids with 16 and 18 carbon atoms. Mixtures or co-feeds of renewablefeedstocks and petroleum-derived hydrocarbons may also be used as thefirst feedstock. Other feedstock components which may be combined intothe first feedstock include spent motor oils and industrial lubricants,used paraffin waxes, liquids derived from the gasification of coal,biomass, natural gas followed by a downstream liquefaction step such asFischer-Tropsch technology, liquids derived from depolymerization,thermal or chemical, of waste plastics such as polypropylene, highdensity polyethylene, and low density polyethylene; and other syntheticoils generated as byproducts from petrochemical and chemical processes.Mixtures of the above may also be used as co-feed components in thefirst feedstock.

The second class of renewable feedstock used herein is a feedstockoriginating from lignocellulose. In the U.S. and worldwide, there arehuge amounts of lignocellulosic material, or biomass, which is notutilized, but is left to decay, often in a landfill, or just in an openfield or forest. The material includes large amounts of wood wasteproducts, and leaves and stalks of crops or other plant material that isregularly discarded and left to decay in fields. The emergence ofinedible lipid-bearing crops for the production of renewable diesel willalso produce increased amounts of biomass post extraction, often knownas meal. Growth of cellulosic ethanol will also produce large amounts ofa lignin side product. Biomass includes, but is not limited to, lignin,plant parts, fruits, vegetables, plant processing waste, wood chips,chaff, grain, grasses, corn, corn husks, weeds, aquatic plants, hay,meal, paper, paper products, recycled paper and paper products, and anycellulose containing biological material or material of biologicalorigin. This biomass material can be pyrolyzed to make a pyrolysis oil,but due to poor thermal stability, the high water content of thepyrolysis oil, often greater than 25%, high total acid number oftengreater than 100, low heating value, and phase incompatibility withpetroleum based materials, pyrolysis oil has found little use other thanas a source of specialty chemicals and as a low grade heating fuel.

The pyrolysis of the biomass to form the pyrolysis oil is achieved byany technique known in the art, see for example, Mohan, D.; Pittman, C.U.; Steele, P. H. Energy and Fuels, 2006, 20, 848-889. Once thepyrolysis oil is generated from the biomass, although optional, it isnot necessary to separate the pyrolysis oil non-aqueous phase from thepyrolysis oil before further processing, thereby eliminating a steppreviously employed in industry. The whole pyrolysis oil may beprocessed, without a portion of the aqueous phase being removed toenrich the pyrolysis oil in the pyrolysis oil non-aqueous phase. Thepyrolytic lignin contains potentially high value products in the form ofaromatic and naphthenic compounds having complex structures thatcomprises aromatic rings that are linked by oxygen atoms or carbonatoms. These structures can be broken into smaller segments whendecarboxylated, decarbonylated, or hydrodeoxygenated, while maintainingthe aromatic ring structures. One desired product is at least one cyclichydrocarbon-rich stream. In one embodiment, this processing of thepyrolytic lignin may be accomplished in the presence of the rest of thepyrolysis oil with no separation of the pyrolytic lignin beforeprocessing required. The pyrolysis oil non-aqueous phase is primarily apyrolysis product of the lignin portion of biomass. It can be separatedfrom the rest of the whole pyrolysis oil during the pyrolysis process orthrough post-processing to produce an additional aqueous phase, whichincludes pyrolysis products primarily from the cellulose andhemicellulose portion of the biomass. The pyrolysis process can convertall components in the biomass feedstock into products useful as fuels orfuel components after full deoxygenation of the pyrolysis oil product.The water soluble components can also be transformed to naphthenes andaromatics under pyrolysis conditions due, for example, to a highconcentration of phenols. Optionally, the pyrolysis oil may be separatedand only a portion of the pyrolysis oil be introduced to thedehydrogenation and deoxygenation zone as the second feedstock.

The first renewable feedstock containing the glycerides and free fattyacids may contain a variety of impurities. For example, tall oil is abyproduct of the wood processing industry and tall oil contains estersand rosin acids in addition to FFAs. Rosin acids are cyclic carboxylicacids. The first renewable feedstock may also contain contaminants suchas alkali metals, e.g. sodium and potassium, phosphorous as well assolids, water and detergents. An optional first step is to remove asmuch of these contaminants as possible before being combined with thesecond renewable feedstock. One possible pretreatment step involvescontacting the first renewable feedstock with an ion-exchange resin in apretreatment zone at pretreatment conditions. The ion-exchange resin isan acidic ion exchange resin such as Amberlyst™-15 and can be used as abed in a reactor through which the first feedstock is flowed through,either upflow or downflow.

Another possible means for removing contaminants from the firstrenewable feedstock is a mild acid wash. This is carried out bycontacting the first renewable feedstock with a solution of water mixedwith an acid such as sulfuric, nitric, phosphoric, or hydrochloric in areactor. The acid and feedstock can be contacted either in a batch orcontinuous process. Contacting is done with a dilute acid solutionusually at ambient temperature and atmospheric pressure. If thecontacting is done in a continuous manner, it is usually done in acounter current manner. Yet another possible means of removing metalcontaminants from the first renewable feedstock is through the use ofguard beds which are well known in the art. These can include aluminaguard beds either with or without demetallation catalysts such as nickelor cobalt. Filtration and solvent extraction techniques are otherchoices which may be employed. Hydroprocessing such as that described inU.S. Ser. No. 11/770,826, hereby incorporated by reference, is anotherpretreatment technique which may be employed.

The first and second renewable feedstocks are flowed to a first reactionzone comprising one or more catalyst beds in one or more reactors. Theterm “feedstock” is meant to include feedstocks that have not beentreated to remove contaminants as well as those feedstocks purified in apretreatment zone. The first and second renewable feedstocks may becombined into a single stream, or each feedstock may be introducedindependently to the first reaction zone. The pyrolysis oil feedstockmay have some water removed, or may be processed as the whole feedstock.The process will be described with reference to the embodiment where thefeedstocks are combined into a single stream which is introduced to thefirst reaction zone. In the reaction first zone, the feedstocks arecontacted with a hydrogenation or hydrotreating catalyst in the presenceof hydrogen at hydrogenation conditions to hydrogenate the reactivecomponents such as olefinic or unsaturated portions of the hydrocarbons.Hydrogenation and hydrotreating catalysts are any of those well known inthe art such as nickel or nickel/molybdenum dispersed on a high surfacearea support. Other hydrogenation catalysts include one or more noblemetal catalytic elements dispersed on a high surface area support.Non-limiting examples of noble metals include Pt and/or Pd dispersed ongamma-alumina or activated carbon. Hydrogenation conditions include atemperature of about 40° C. to about 400° C. and a pressure of about 689kPa absolute (100 psia) to about 13,790 kPa absolute (2000 psia). Inanother embodiment the hydrogenation conditions include a temperature ofabout 200° C. to about 300° C. and a pressure of about 1379 kPa absolute(200 psia) to about 4826 kPa absolute (700 psia). Other operatingconditions for the hydrogenation zone are well known in the art.

The catalysts enumerated above are also capable of catalyzingdecarboxylation, decarbonylation and/or hydrodeoxygenation of thefeedstock to remove oxygen. Decarboxylation, decarbonylation, andhydrodeoxygenation are herein collectively referred to as deoxygenationreactions. Decarboxylation conditions include a relatively low pressureof about 689 kPa (100 psia) to about 13,790 kPa (2000 psia), atemperature of about 200° C. to about 400° C. and a liquid hourly spacevelocity of about 0.5 to about 10 hr⁻¹. In another embodiment thedecarboxylation conditions include the same relatively low pressure ofabout 689 kPa (100 psia) to about 6895 kPa (1000 psia), a temperature ofabout 288° C. to about 345° C. and a liquid hourly space velocity ofabout 1 to about 4 hr⁻¹. Since hydrogenation is an exothermic reaction,as the feedstocks flow through the catalyst bed(s) the temperatureincreases and decarboxylation and hydrodeoxygenation will begin tooccur. Thus, it is envisioned and is within the scope of this inventionthat all the reactions occur simultaneously in one reactor or in onebed. Alternatively, the conditions can be controlled such thathydrogenation primarily occurs in one bed and decarboxylation and/orhydrodeoxygenation occurs in a second bed. Of course if only one bed isused, then hydrogenation occurs primarily at the front of the bed, whiledecarboxylation/hydrodeoxygenation occurs mainly in the middle andbottom of the bed. Finally, desired hydrogenation can be carried out inone reactor, while decarboxylation, decarbonylation, and/orhydrodeoxygenation can be carried out in a separate reactor.

The first reaction zone performs catalytic decarboxylation,decarbonylation, and hydrodeoxygenation of oxygen polymers and singleoxygenated molecules in the pyrolysis oil and trigylcerides by breakingthe oxygen linkages, and forming water and CO₂ from the oxygen andleaving smaller molecules. For example, the phenylpropyl ether linkagesin the pyrolysis oil non-aqueous phase will be partially deoxygenatedproducing some aromatic rings, such as alkylbenzenes andpolyalkylbenzenes. Very reactive oxygenates will be deoxygenated aswell, including small molecular weight carboxylic acids thereforegreatly increasing the thermal stability of the product. Pyrolysis oilcomponents not derived from lignin, including cellulose, hemicellulose,free sugars, may yield products such as acetic acid, furfural, furan,levoglucosan, 5-hydroxymethylfurfural, hydroxyacetaldehyde,formaldehyde, and others such as those described in Mohan, D.; Pittman,C. U.; Steele, P. H. Energy and Fuels, 2006, 20, 848-889. Therefore,pyrolysis oil components not derived from lignin will also be partiallyor fully deoxygenated to produce a significant amount of lighthydrocarbon fractions and water. The light hydrocarbon fractions maycontain hydrocarbons with six or fewer carbon atoms. The paraffinsresulting from the deoxygenation of the triglycerides may contain fromabout 15 to about 18 or from 8 to about 18 carbon atoms depending uponthe source of the renewable feedstock. The reactions of decarbonylation,decarboxylation and hydrodeoxygenation are collectively referred to asdeoxygenation reactions. Hydrogenation of olefins also occur in thiszone.

The reaction product from the hydrogenation and deoxygenation reactionswill comprise both a liquid portion and a gaseous portion. The liquidportion comprises a hydrocarbon fraction comprising n-paraffins andhaving a large concentration of paraffins in the 15 to 18 carbon numberrange resulting from the hydrogenation and deoxygenation of thetriglyceride and free fatty acid feedstock; and a wide boiling range ofpredominately cyclic hydrocarbons resulting from the hydrogenation anddeoxygenation of the pyrolysis oil feedstock. Different triglyceride andfree fatty acid feedstocks will result in different distributions ofcomponents. A portion of this hydrocarbon fraction, after separationfrom the gaseous portion, may be used as the hydrocarbon recycledescribed below. Although this hydrocarbon fraction is useful as adiesel fuel or diesel fuel blending component, additional fuels, such asaviation fuels or aviation fuel blending components which typically havea concentration of paraffins in the range of about 9 to about 15 carbonatoms, may be produced with additional processing. Also, because thehydrocarbon fraction contains a large amount of n-paraffins, it may havepoor cold flow properties. Many diesel and aviation fuels and blendingcomponents must have better cold flow properties and so the reactionproduct is further reacted under isomerization conditions to isomerizeat least a portion of the n-paraffins to branched paraffins.

In another embodiment, the combined feedstock containing both thetriglycerides and free fatty acids and the pyrolysis oil is fullydeoxygenated in two separate zones, a partial deoxygenation zone and afull deoxygenation zone. The partial deoxygenation zone may also beconsidered to be a hydrotreating zone and the full deoxygenation zonemay be considered to be a hydrocracking zone. “Full” deoxygenation ismeant to include deoxygenating at least 99% to 100% of availableoxygenated hydrocarbons. For this embodiment, the zones will primarilybe referred to herein as a partial deoxygenation zone and a fulldeoxygenation zone. In the partial deoxygenation zone, partialdeoxygenation occurs at milder conditions than the full deoxygenationzone and uses a catalyst such as a hydrotreating catalyst. In general,the partial oxidation zone removes the most reactive and thermallyinstable oxygenates. The catalysts and conditions of the partialdeoxygenation zone are selected so that the more reactive compounds aredeoxygenated while minimizing the thermal polymerization well known tooccur in pyrolysis oils subjected to high temperatures. The oxygen levelof the combined feedstock, which typically ranges form about 10 to about50 wt. % is reduced to a significantly lower level, from about 5 toabout 20 wt. % in the partial deoxygenation zone. Water is reduced fromthe combined feedstock levels of from about 10 to about 30 wt. % tolevels from about 1 wt. % to about 10 wt. %. The acidity is greatlyreduced as well in the partial deoxygenation zone, from a Total AcidNumber (TAN), as determined by ASTM D664, level of about 125 mg KOH/g toabout 200 mg KOH/g in the feedstock to a reduced level from about 20 mgKOH/g to about 100 mg KOH/g in the partial deoxygenation zone effluent.

The more thermally stable effluent from the partial deoxygenation zonecan then be fully deoxygenated in the full deoxygenation zone. In thefull deoxygenation zone a first hydroprocessing catalyst is employedwith the option of more severe process conditions in order to catalyzethe deoxygenation of less reactive oxygenates. Some hydrocracking offeedstock molecules will also occur to a higher extent than in thepartial deoxygenation zone. In the full deoxygenation zone, oxygencontent is reduced from about 5 wt. % to about 20 wt. % to much lowerlevels, from ppm concentrations to about 0.5 wt. %. Water is alsogreatly reduced in the full deoxygenation zone, from about 1 wt. % toabout 10 wt. % down to levels from about 100 ppm to about 1000 ppm. Theacidity is greatly reduced from initial Total Acid Number (TAN), asdetermined by ASTM D664, levels of about 20 to about 100 mg KOH/g tolower levels from about 0.01 to about 4 mg KOH/g. The effluent of thefull deoxygenation zone is a hydrocarbon mixture rich in paraffins,naphthenes and aromatics.

Optionally, when employing the embodiment where the hydrogenation anddeoxygenation are conducted in two zones, partially deoxygenatedeffluent may be passed to a separation zone before being introduced tothe full deoxygenation zone. Carbon oxides, possibly hydrogen sulfide,and C3 and lighter components are separated and removed in an overheadline and a partially deoxygenated product stream is removed from theseparation zone. The separation zone may comprise a separator. Dependingupon whether the separator is operated in a hot or cold mode, the watermay be removed as a vapor (hot separator mode) or as a liquid (coldseparator mode). The overhead comprises a large quantity of hydrogen andat least the carbon dioxide from the decarboxylation reaction. Thecarbon dioxide can be removed from the hydrogen by means well known inthe art such as reaction with a hot carbonate solution, pressure swingabsorption, etc. Also, absorption with an amine in processes such asdescribed in co-pending applications U.S. Ser. No. 12/193,172 and U.S.Ser. No. 12/193,196 hereby incorporated by reference, may be employed.If desired, essentially pure carbon dioxide can be recovered byregenerating the spent absorption media. Therefore the overhead ispassed through one or more scrubbers such as amine scrubbers to removecarbon dioxide and hydrogen sulfide. Depending upon the scrubbertechnology selected some portion of water may also be retained by thescrubber. The lighter hydrocarbons and gasses, possibly including aportion of water, are conducted to steam reforming zone. In oneembodiment the light hydrocarbon fractions may contain hydrocarbons withsix or fewer carbon atoms. After purification, hydrogen generated in thesteam reforming zone is conducted to combine with feedstock andpartially deoxygenated product stream. The hydrogen may be recycled tocombine with the feedstock as shown or may be introduced directly to thereaction zone where hydrogenation primarily occurs and/or to anysubsequent reactor beds.

The partially deoxygenated product stream along with recycle hydrogenstream and optional hydrocarbon recycle, is passed to a secondhydrodeoxygenation zone, where the remaining oxygen is removed. The fulldeoxygenation zone performs catalytic decarboxylation, decarbonylation,and hydrodeoxygenation of the remaining oxygen compounds that are morestable than those reacted in the first stage. The same or differenthydroprocessing catalyst may be used as compared to the partialdeoxygenation zone. In one embodiment, a more active catalyst and moresevere process conditions are employed in the full deoxygenation zone ascompared to the partial deoxygenation zone in order to catalyze fulldeoxygenation.

As mentioned above, the effluent of the hydrogenation and deoxygenationzone comprises a liquid hydrocarbon portion and a gaseous portion. Thegaseous portion comprises hydrogen, carbon dioxide, carbon monoxide,water vapor, propane and perhaps sulfur components such as hydrogensulfide or possibly a phosphorous component such as phosphine. In oneembodiment, such as the single stage deoxygenation embodiment, theeffluent from the deoxygenation zone is conducted to a hot high pressurehydrogen stripper. One purpose of the hot high pressure hydrogenstripper is to selectively separate at least a portion of the gaseousportion of the effluent from the liquid portion of the effluent. Ashydrogen is an expensive resource, to conserve costs, the separatedhydrogen is recycled to the first reaction zone containing thedeoxygenation reactor(s). Also, failure to remove the water, carbonmonoxide, and carbon dioxide from the effluent may result in poorcatalyst performance in a downstream zone such as the optionalisomerization zone. Water, carbon monoxide, carbon dioxide, any ammoniaor hydrogen sulfide are selectively stripped in the hot high pressurehydrogen stripper using hydrogen. The hydrogen used for the strippingmay be dry, and free of carbon oxides. The temperature may be controlledin a limited range to achieve the desired separation and the pressuremay be maintained at approximately the same pressure as the two reactionzones to minimize both investment and operating costs. The hot highpressure hydrogen stripper may be operated at conditions ranging from apressure of about 689 kPa absolute (100 psia) to about 13,790 kPaabsolute (2000 psia), and a temperature of about 40° C. to about 350° C.In another embodiment the hot high pressure hydrogen stripper may beoperated at conditions ranging from a pressure of about 1379 kPaabsolute (200 psia) to about 4826 kPa absolute (700 psia), or about 2413kPa absolute (350 psia) to about 4882 kPa absolute (650 psia), and atemperature of about 50° C. to about 350° C. The hot high pressurehydrogen stripper may be operated at essentially the same pressure asthe reaction zone. By “essentially”, it is meant that the operatingpressure of the hot high pressure hydrogen stripper is within about 1034kPa absolute (150 psia) of the operating pressure of the reaction zone.For example, in one embodiment the hot high pressure hydrogen stripperseparation zone is no more than 1034 kPa absolute (150 psia) less thanthat of the reaction zone.

The effluent enters the hot high pressure stripper and at least aportion of the gaseous components, are carried with the hydrogenstripping gas and separated into an overhead stream. The remainder ofthe deoxygenation zone effluent stream is removed as hot high pressurehydrogen stripper bottoms and contains the liquid hydrocarbon fractionhaving components such as normal and isomerized hydrocarbons having fromabout 8 to 24 carbon atoms, a wide range of cycloparaffins and aromaticswith a boiling point range from about 25 to about 400° C., and someheavier cyclic hydrocarbons with a boiling point range from about 400 toabout 600° C. A portion of this liquid hydrocarbon fraction in hot highpressure hydrogen stripper bottoms may be used as the hydrocarbonrecycle described below.

In some embodiments, a portion of the lighter hydrocarbons generated inthe deoxygenation zone may be also carried with the hydrogen in the hothigh pressure hydrogen stripper and removed in the overhead stream. Anyhydrocarbons removed in the overhead stream will effectively bypass theoptional isomerization zone, discussed below. Some of the hydrocarbonsbypassing the optional isomerization zone may be normal hydrocarbonswhich, due to bypassing the isomerization stage, will not be isomerizedto branched hydrocarbons. At least a portion of these normalhydrocarbons may ultimately end up in the diesel range product or theaviation range product, and depending upon the specifications requiredfor the products, the normal hydrocarbons may have an undesired effecton the diesel range product and the aviation range product. For example,in applications where the diesel range product is required to meetspecific cloud point specifications, or where the aviation range productis required to meet specific freeze point specifications, the normalhydrocarbons from the hot high pressure hydrogen stripper overhead mayinterfere with meeting the required specification.

Therefore, in some embodiments it is advantageous to take steps toprevent normal hydrocarbons from being removed in the hot high pressurehydrogen stripper overhead and bypassing the isomerization zone. Forexample, one or more, or a mixture of additional rectification agentsmay be optionally introduced into the hot high pressure hydrogenstripper to reduce the amount of hydrocarbons in the hot high pressurehydrogen stripper overhead stream. Suitable example of additionalrectification agents include the diesel boiling point range product, theaviation boiling point range product, the naphtha/gasoline boiling rangeproduct, the mixture of naphtha/gasoline and LPG, or any combinationsthereof. These streams may be recycled and introduced to the hot highpressure hydrogen stripper, at a location of the stripper that is abovethe deoxygenation zone effluent introduction location and in therectification zone. The rectification zone, if present, may containvapor liquid contacting devices such as trays or packing to increase theefficiency of the rectification. The optional rectification agent wouldoperate to force an increased amount of the hydrocarbon product from thedeoxygenation zone to travel downward in the hot high pressure hydrogenstripper and be removed in the hot high pressure hydrogen stripperbottoms stream instead of being carried with the stripping hydrogen gasinto the hot high pressure hydrogen stripper overhead. Otherrectification agents from independent sources may be used instead of, orin combination with, the diesel boiling point range product, thenaphtha/gasoline product, and the naphtha/gasoline and LPG stream.

In another embodiment, a separator may be used to separate the gaseousportion of the effluent from the liquid portion of the effluent.

Hydrogen is a reactant in at least some of the reactions above, and asufficient quantity of hydrogen must be in solution to most effectivelytake part in the catalytic reaction. Past processes have operated athigh pressures in order to achieve a desired amount of hydrogen insolution and readily available for reaction. However, higher pressureoperations are more costly to build and to operate as compared to theirlower pressure counterparts. One advantage of an embodiment of theinvention is the operating pressure may be in the range of about 1379kPa absolute (200 psia) to about 4826 kPa absolute (700 psia) which islower than that found in other previous operations. In anotherembodiment the operating pressure is in the range of about 2413 kPaabsolute (350 psia) to about 4481 kPa absolute (650 psia), and in yetanother embodiment operating pressure is in the range of about 2758 kPaabsolute (400 psia) to about 4137 kPa absolute (600 psia). Furthermore,the rate of reaction is increased resulting in a greater amount ofthroughput of material through the reactor in a given period of time.

In one embodiment, the desired amount of hydrogen is kept in solution atlower pressures by employing a large recycle of hydrocarbon to thehydrogenation and deoxygenation reaction zone. A hydrocarbon recycle mayalso be employed in order to control the temperature in the reactionzones since the reactions are exothermic reactions. Hydrogen has agreater solubility in the hydrocarbon product than it does in thefeedstock. By utilizing a large hydrocarbon recycle the solubility ofhydrogen in the combined liquid phase in the reaction zone is greatlyincreased and higher pressures are not needed to increase the amount ofhydrogen in solution. In one embodiment of the invention, the volumeratio of hydrocarbon recycle to feedstock is from about 2:1 to about8:1. In another embodiment the ratio is in the range of about 3:1 toabout 6:1 and in yet another embodiment the ratio is in the range ofabout 4:1 to about 5:1.

Although the hydrocarbon fraction separated from the deoxygenation zoneeffluent may be useful as a fuel or fuel blending component, because itmay comprise a large amount of n-paraffins, it may have poor cold flowproperties. Also, depending upon the feedstock, the amount ofhydrocarbons suitable for aviation fuel or aviation fuel blendingcomponent may be small. Therefore the hydrocarbon fraction mayoptionally be contacted with an isomerization catalyst underisomerization conditions to at least partially isomerize the n-paraffinsto branched paraffins and improve the cold flow properties of the liquidhydrocarbon fraction. The isomerization catalysts and operatingconditions may optionally be selected so that the isomerization catalystalso catalyzes selective hydrocracking of the paraffins. The selectivehydrocracking also creates hydrocarbons in the aviation boiling pointrange. The effluent of the second reaction zone, the isomerization andselective hydrocracking zone, is enriched in branched-paraffins.Isomerization and selective hydrocracking can be carried out in aseparate bed of the same reactor, described above or the isomerizationand selective hydrocracking can be carried out in a separate reactor.For ease of description, the following will address the embodiment wherea second reactor is employed for the isomerization and selectivehydrocracking reactions. The hydrogen stripped product of thedeoxygenation reaction zone is contacted with an isomerization andselective hydrocracking catalyst in the presence of hydrogen atisomerization and selective hydrocracking conditions to isomerize atleast a portion of the normal paraffins to branched paraffins. Due tothe presence of hydrogen, the reactions may be called hydroisomerizationand hydrocracking.

The isomerization and selective hydrocracking of the hydrogenation anddeoxygenation product can be accomplished in any manner known in the artor by using any suitable catalyst known in the art. One or more beds ofcatalyst may be used. It is preferred that the isomerization be operatedin a co-current mode of operation. Fixed bed, trickle bed down flow orfixed bed liquid filled up-flow modes are both suitable. See also, forexample, US 2004/0230085 A1 which is incorporated by reference in itsentirety. Catalysts having an acid function and mild hydrogenationfunction are favorable for catalyzing both the isomerization reactionand the selective hydrocracking reaction. Suitable catalysts comprise ametal of Group VIII (IUPAC8-10) of the Periodic Table and a supportmaterial. Suitable Group VIII metals include platinum and palladium,each of which may be used alone or in combination. The support materialmay be amorphous or crystalline or a combination of the two. Suitablesupport materials include amorphous alumina, amorphous silica-alumina,ferrierite, ALPO-31, SAPO-11, SAPO-31, SAPO-37, SAPO-41, SM-3,MgAPSO-31, FU-9, NU-10, NU-23, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-48,ZSM-50, ZSM-57, MeAPO-11, MeAPO-31, MeAPO-41, MeAPSO-11, MeAPSO-31,MeAPSO-41, MeAPSO-46, ELAPO-11, ELAPO-31, ELAPO-41, ELAPSO-11,ELAPSO-31, ELAPSO-41, laumontite, cancrinite, offretite, hydrogen formof stillbite, magnesium or calcium form of mordenite, and magnesium orcalcium form of partheite, each of which may be used alone or incombination. ALPO-31 is described in U.S. Pat. No. 4,310,440. SAPO-11,SAPO-31, SAPO-37, and SAPO-41 are described in U.S. Pat. No. 4,440,871.SM-3 is described in U.S. Pat. Nos. 4,943,424; 5,087,347; 5,158,665; and5,208,005. MgAPSO is a MeAPSO, which is an acronym for a metalaluminumsilicophosphate molecular sieve, where the metal Me is magnesium(Mg). Suitable MeAPSO-31 catalysts include MgAPSO-31. MeAPSOs aredescribed in U.S. Pat. No. 4,793,984, and MgAPSOs are described in U.S.Pat. No. 4,758,419. MgAPSO-31 is a preferred MgAPSO, where 31 means aMgAPSO having structure type 31. Many natural zeolites, such asferrierite, that have an initially reduced pore size can be converted toforms suitable for selective hydrocracking and isomerization by removingassociated alkali metal or alkaline earth metal by ammonium ion exchangeand calcination to produce the substantially hydrogen form, as taught inU.S. Pat. No. 4,795,623 and 4,924,027. Further catalysts and conditionsfor skeletal isomerization are disclosed in U.S. Pat. Nos. 5,510,306,5,082,956, and 5,741,759.

The isomerization and selective hydrocracking catalyst may also comprisea modifier selected from the group consisting of lanthanum, cerium,praseodymium, neodymium, phosphorus, samarium, gadolinium, terbium, andmixtures thereof, as described in U.S. Pat. No. 5,716,897 and U.S. Pat.No. 5,851,949. Other suitable support materials include ZSM-22, ZSM-23,and ZSM-35, which are described for use in dewaxing in U.S. Pat. No.5,246,566 and in the article entitled “New molecular sieve process forlube dewaxing by wax isomerization,” written by S. J. Miller, inMicroporous Materials 2 (1994) 439-449. The teachings of U.S. Pat. Nos.4,310,440; 4,440,871; 4,793,984; 4,758,419; 4,943,424; 5,087,347;5,158,665; 5,208,005; 5,246,566; 5,716,897; and 5,851,949 are herebyincorporated by reference.

U.S. Pat. Nos. 5,444,032 and 5,608,134 teach a suitable bifunctionalcatalyst which is constituted by an amorphous silica-alumina gel and oneor more metals belonging to Group VIIIA, and is effective in thehydroisomerization of long-chain normal paraffins containing more than15 carbon atoms. An activated carbon catalyst support may also be used.U.S. Pat. No. 5,981,419 and U.S. Pat. No. 5,968,344 teach a suitablebifunctional catalyst which comprises: (a) a porous crystalline materialisostructural with beta-zeolite selected from boro-silicate (BOR—B) andboro-alumino-silicate (Al—BOR—B) in which the molar SiO₂:Al₂O₃ ratio ishigher than 300:1; (b) one or more metal(s) belonging to Group VIIIA,selected from platinum and palladium, in an amount comprised within therange of from 0.05 to 5% by weight. Article V. Calemma et al., App.Catal. A: Gen., 190 (2000), 207 teaches yet another suitable catalyst.

The isomerization and selective hydrocracking catalyst may be any ofthose well known in the art such as those described and cited above.Isomerization and selective cracking conditions include a temperature ofabout 150° C. to about 360° C. and a pressure of about 1724 kPa absolute(250 psia) to about 4726 kPa absolute (700 psia). In another embodimentthe isomerization conditions include a temperature of about 300° C. toabout 360° C. and a pressure of about 3102 kPa absolute (450 psia) toabout 3792 kPa absolute (550 psia). Other operating conditions for theisomerization and selective hydrocracking zone are well known in theart. Some known isomerization catalysts, when operated under more severeconditions, also provide the selective hydrocracking catalytic function.

The isomerization and selective cracking zone effluent is processedthrough one or more separation steps to obtain at least two purifiedhydrocarbon streams, one useful as a diesel fuel or a diesel fuelblending component and the second useful as aviation fuel or an aviationfuel blending component. It is likely that the separation steps could beused to produce and additional purified hydrocarbon stream useful as agasoline fuel or gasoline fuel blending component. Depending upon theapplication, various additives may be combined with the diesel oraviation fuel composition generated in order to meet requiredspecifications for different specific fuels. In particular, the aviationfuel produced would have the same physical properties and performancecharacteristics as aviation fuel qualified to meet at least one of: ASTMD 1655 Specification for Aviation Turbine Fuels Defense Stan 91-91Turbine Fuel, Aviation Kerosene Type, Jet A-1 NATO code F-35, F-34, F-37Aviation Fuel Quality Requirements for Jointly Operated Systems (JointChecklist) A combination of ASTM and Def Stan requirements GOST 10227Jet Fuel Specifications (Russia) Canadian CAN/CGSB-3.22 Aviation TurbineFuel, Wide Cut Type Canadian CAN/CGSB-3.23 Aviation Turbine Fuel,Kerosene Type MIL-DTL-83133, JP-8, MIL-DTL-5624, JP-4, JP-5 QAV-1(Brazil) Especifcacao de Querosene de Aviacao No. 3 Jet Fuel (Chinese)according to GB6537 DCSEA 134A (France) Carbureacteur Pour TurbomachinesD′Aviation, Type Kerosene Aviation Turbine Fuels of other countries,meeting the general grade requirements for Jet A, Jet A-1, Jet B, andTS-1 fuels as described in the IATA Guidance Material for AviationTurbine Fuel Specifications. The aviation fuel is generally termed “jetfuel” herein and the term “jet fuel” is meant to encompass aviation fuelmeeting the specifications above as well as to encompass aviation fuelused as a blending component of an aviation fuel meeting thespecifications above. Additives may be added to the jet fuel in order tomeet particular specifications. One particular type of jet fuel is JP-8,defined by Military Specification MIL-DTL-83133, which is a militarygrade type of highly refined kerosene based jet propellant specified bythe United States Government. The fuel produced from glycerides or FFAsis very similar to SPK, also known as a synthetic paraffinic kerosene.

The specifications for different types of fuels are often expressedthrough acceptable ranges of chemical and physical requirements of thefuel. As stated above, aviation turbine fuels, a kerosene type fuelincluding JP-8, are specified by MIL-DTL-83133, JP-4, a blend ofgasoline, kerosene and light distillates, is specified by MIL-DTL-5624and JP-5 a kerosene type fuel with low volatility and high flash pointis also specified by MIL-DTL-5624, with the written specification ofeach being periodically revised. Often a distillation range from 10percent recovered to a final boiling point is used as a key parameterdefining different types of fuels. The distillations ranges aretypically measured by ASTM Test Method D 86 or D2887. Therefore,blending of different components in order to meet the specification isquite common. While the product of the present invention may meet fuelspecifications, in some cases, blending of the product with otherblending components may be required to meet the desired set of fuelspecifications. In other words, the aviation product of this inventionis a composition which may be used with other components to form a fuelmeeting at least one of the specifications for aviation fuel such asJP-8.

With the effluent stream of either the deoxygenation zone or theoptional isomerization and selective hydrocracking zone comprising botha liquid component and a gaseous component, various portions of whichmay be recycled, multiple separation steps may be employed. For example,hydrogen may be first separated in an effluent separator with theseparated hydrogen being removed in an overhead stream. Suitableoperating conditions of the isomerization effluent separator include,for example, a temperature of 230° C. and a pressure of 4100 kPaabsolute (600 psia). If there is a low concentration of carbon oxides,or the carbon oxides are removed, the hydrogen may be recycled back tothe hot high pressure hydrogen stripper for use both as a rectificationgas and to combine with the remainder as a bottoms stream. Or, thehydrogen may be passed to the deoxygenation or isomerization reactionzones and thus the hydrogen becomes a component of the reaction zonefeed streams in order to provide the necessary hydrogen partialpressures for the reactor. Different feedstocks will consume differentamounts of hydrogen. The effluent separator allows flexibility for theprocess to operate even when larger amounts of hydrogen are consumed inthe first reaction zone. Furthermore, at least a portion of theremainder or bottoms stream of the effluent separator may be recycled tothe deoxygenation zone or the optional isomerization zone to perhapsincrease the degree of isomerization.

The remainder of the effluent of either the isomerization and selectivehydrocracking zone or the hydrogenation and deoxygenation zone, afterthe removal of hydrogen, still has liquid and gaseous components and iscooled, by techniques such as air cooling or water cooling and passed toa cold separator where the liquid component is separated from thegaseous component. Suitable operating conditions of the cold separatorinclude, for example, a temperature of about 20 to 60° C. and a pressureof 3850 kPa absolute (560 psia). A water byproduct stream is alsoseparated. At least a portion of the liquid component, after cooling andseparating from the gaseous component, may be recycled back to theisomerization zone to increase the degree of isomerization. Prior toentering the cold separator, the remainder of the effluent may becombined with the hot high pressure hydrogen stripper overhead stream,and the resulting combined stream may be introduced into the coldseparator.

The liquid component contains the hydrocarbons useful as diesel fuel ordiesel fuel blending components, aviation fuel or aviation fuel blendingcomponents, gasoline fuel or gasoline fuel blending components, termeddiesel boiling point range product, aviation boiling point rangeproduct, and gasoline boiling range product respectively, as well asamounts of LPG. The separated liquid component is further purified in aproduct distillation zone which separates lower boiling components anddissolved gases into an LPG and naphtha/gasoline boiling point rangestream; an aviation boiling point range product; and a diesel boilingpoint range product. Suitable operating conditions of the productdistillation zone include a temperature of from about 20 to about 200°C. at the overhead and a pressure from about 0 to about 1379 kPaabsolute (0 to 200 psia). The conditions of the distillation zone may beadjusted to control the relative amounts of hydrocarbon contained in theaviation boiling point range product stream, the diesel boiling pointrange product stream, and the LPG and naphtha/gasoline boiling pointrange stream.

The LPG and naphtha/gasoline stream may be further separated in adebutanizer or depropanizer in order to separate the LPG into anoverhead stream, leaving the naphtha/gasoline in a bottoms stream.Suitable operating conditions of this unit include a temperature of fromabout 20 to about 200° C. at the overhead and a pressure from about 0 toabout 2758 kPa absolute (0 to 400 psia). The LPG may be sold as valuableproduct or may be used in other processes such as a feed to a hydrogenproduction facility. The gasoline boiling point range stream may becollected as product or may be used in other processes. Optionally, theconditions of the distillation zone may be adjusted so that the gasolineboiling point range hydrocarbons are removed as a side cut as opposed tobeing removed with the LPG thus avoiding a debutanizer or depropanizer.

The gaseous component separated in the product separator comprisesmostly hydrogen and the carbon dioxide from the decarboxylationreaction. Other components such as carbon monoxide, propane, andhydrogen sulfide or other sulfur containing component may be present aswell. It is desirable to recycle the hydrogen to the isomerization zone,but if the carbon dioxide was not removed, its concentration wouldquickly build up and effect the operation of the isomerization zone. Thecarbon dioxide can be removed from the hydrogen by means well known inthe art such as reaction with a hot carbonate solution, pressure swingabsorption, etc. Amine absorbers may be employed as taught in copendingU.S. applications U.S. application Ser. No. 12/193,176 and U.S.application Ser. No. 12/193,196 hereby incorporated by reference. Ifdesired, essentially pure carbon dioxide can be recovered byregenerating the spent absorption media.

Similarly, a sulfur containing component such as hydrogen sulfide may bepresent to maintain the sulfided state of the deoxygenation catalyst orto control the relative amounts of the decarboxylation reaction and thehydrogenation reaction that are both occurring in the deoxygenationzone. The amount of sulfur is generally controlled and so must beremoved before the hydrogen is recycled. The sulfur components may beremoved using techniques such as absorption with an amine or by causticwash. Of course, depending upon the technique used, the carbon dioxideand sulfur containing components, and other components, may be removedin a single separation step such as a hydrogen selective membrane.

The hydrogen remaining after the removal of at least carbon dioxide maybe recycled to the reaction zone where hydrogenation primarily occursand/or to any subsequent beds or reactors. The recycle stream may beintroduced to the inlet of the reaction zone and/or to any subsequentbeds or reactors. One benefit of the hydrocarbon recycle is to controlthe temperature rise across the individual beds. However, as discussedabove, the amount of hydrocarbon recycle may be determined based uponthe desired hydrogen solubility in the reaction zone which is in excessof that used for temperature control. Increasing the hydrogen solubilityin the reaction mixture allows for successful operation at lowerpressures, and thus reduced cost.

As discussed above, at least a portion of the diesel boiling point rangeproduct; at least a portion of the aviation boiling point range product,at least a portion of the LPG and naphtha/gasoline stream; at least aportion of a naphtha/gasoline stream or an LPG stream generated byseparating the LPG and naphtha/gasoline stream into an LPG stream andthe naphtha/gasoline stream; or any combination thereof may be recycledto the optional rectification zone of the hot high pressure hydrogenstripper.

The following embodiments are presented in illustration of the processand are not intended as an undue limitation on the generally broad scopeof the invention as set forth in the claims.

Turning to FIG. 1, the process for generating the paraffin richcomponent begins with a renewable feedstock stream 2 which may passthrough an optional feed surge drum. The renewable feedstock 2 is amixture of two different types of renewable feedstocks, one beingprimarily triglycerides and fatty acids and the other being pyrolysisoil. The feedstock stream is combined with recycle gas stream 68 andrecycle stream 16 to form combined feed stream 20, which is heatexchanged with reactor effluent and then introduced into deoxygenationreactor 4. The heat exchange may occur before or after the recycle iscombined with the feed.

Deoxygenation reactor 4 may contain multiple beds shown in FIGS. 2 as 4a, 4 b and 4 c. Deoxygenation reactor 4 contains at least one catalystcapable of catalyzing decarboxylation and/or hydrodeoxygenation of thefeedstock to remove oxygen. Deoxygenation reactor effluent stream 6containing the products of the decarboxylation and/or hydrodeoxygenationreactions is removed from deoxygenation reactor 4 and heat exchangedwith stream 20 containing feed to the deoxygenation reactor. Stream 6comprises a liquid component containing largely normal paraffinhydrocarbons in the diesel boiling point range and a wide range ofcycloparaffins and aromatics and a gaseous component containing largelyhydrogen, vaporous water, carbon monoxide, carbon dioxide and propane.

Deoxygenation reactor effluent stream 6 is then directed to hot highpressure hydrogen stripper 8. Make up hydrogen in line 10 is dividedinto two portions, stream 10 a and 10 b. Make up hydrogen in stream 10 ais also introduced to hot high pressure hydrogen stripper 8. In hot highpressure hydrogen stripper 8, the gaseous component of deoxygenationreactor effluent 6 is selectively stripped from the liquid component ofdeoxygenation reactor effluent 6 using make-up hydrogen 10 a and recyclehydrogen 28. The dissolved gaseous component comprising hydrogen,vaporous water, carbon monoxide, carbon dioxide hydrogen sulfide, and atleast a portion of the methane, ethane and propane, is selectivelyseparated into hot high pressure hydrogen stripper overhead stream 14.The remaining liquid component of deoxygenation reactor effluent 6comprising primarily normal paraffins having a carbon number from about8 to about 24 and a wide range of cycloparaffins and aromatics with aboiling point range of about 25° C. to about 400° C., and some heaviercyclic hydrocarbons with a boiling point range from about 400° C. toabout 600° C. is removed as hot high pressure hydrogen stripper bottom12.

A portion of hot high pressure hydrogen stripper bottoms forms recyclestream 16 and is combined with renewable feedstock stream 2 to createcombined feed 20. Another portion of recycle stream 16, optional stream16 a, may be routed directly to deoxygenation reactor 4 and introducedat interstage locations such as between beds 4 a and 4 b and or betweenbeds 4 b and 4 c in order, or example, to aid in temperature control.The remainder of hot high pressure hydrogen stripper bottoms in stream12 is combined with hydrogen stream 10 b to form combined stream 18which is routed to the optional isomerization and selectivehydrocracking reactor 22. Stream 18 may be heat exchanged withisomerization reactor effluent 24.

The product of the optional isomerization and selective hydrocrackerreactor containing a gaseous portion of hydrogen and light hydrocarbonsand a branched-paraffin-enriched liquid portion is removed in line 24,and after optional heat exchange with stream 18, is introduced intohydrogen separator 26. The overhead stream 28 from hydrogen separator 26contains primarily hydrogen which may be recycled back to hot highpressure hydrogen stripper 8. Bottom stream 30 from hydrogen separator26 is air cooled using air cooler 32 and introduced into productseparator 34. In product separator 34 the gaseous portion of the streamcomprising hydrogen, carbon monoxide, hydrogen sulfide, carbon dioxideand propane are removed in stream 36 while the liquid hydrocarbonportion of the stream is removed in stream 38. A water byproduct stream40 may also be removed from product separator 34. Stream 38 isintroduced to product stripper 42 where components having higherrelative volatilities are separated into stream 44, components withinthe boiling range of aviation fuel is removed in stream 45, with theremainder, the diesel range components, being withdrawn from productstripper 42 in line 46. Optionally, a portion of the diesel rangecomponents in line 46 are recycled in line 46 a to hot high pressurehydrogen stripper 8 optional rectification zone 23 and used as anadditional rectification agent. Stream 44 is introduced intofractionator 48 which operates to separate LPG into overhead 50 leavinga naphtha/gasoline bottoms 52. Any of optional lines 72, 74, or 76 maybe used to recycle at least a portion of the isomerization zone effluentback to the isomerization zone to increase the amount of n-paraffinsthat are isomerized to branched paraffins.

The vapor stream 36 from product separator 34 contains the gaseousportion of the isomerization effluent which comprises at least hydrogen,carbon monoxide, hydrogen sulfide, carbon dioxide and propane and isdirected to a system of amine absorbers to separate carbon dioxide andhydrogen sulfide from the vapor stream. Because of the cost of hydrogen,it is desirable to recycle the hydrogen to deoxygenation reactor 4, butit is not desirable to circulate the carbon dioxide or an excess ofsulfur containing components. In order to separate sulfur containingcomponents and carbon dioxide from the hydrogen, vapor stream 36 ispassed through a system of at least two amine absorbers, also calledscrubbers, starting with the first amine absorber zone 56. The aminechosen to be employed in first amine scrubber 56 is capable ofselectively removing at least both the components of interest, carbondioxide and the sulfur components such as hydrogen sulfide. Suitableamines are available from DOW and from BASF, and in one embodiment theamines are a promoted or activated methyldiethanolamine (MDEA). See U.S.Pat. No. 6,337,059, hereby incorporated by reference in its entirety.Suitable amines for the first amine absorber zone from DOW include theUCARSOL™ AP series solvents such as AP802, AP804, AP806, AP810 andAP814. The carbon dioxide and hydrogen sulfide are absorbed by the aminewhile the hydrogen passes through first amine scrubber zone and intoline 68 to be recycled to the first reaction zone. The amine isregenerated and the carbon dioxide and hydrogen sulfide are released andremoved in line 62. Within the first amine absorber zone, regeneratedamine may be recycled for use again. The released carbon dioxide andhydrogen sulfide in line 62 are passed through second amine scrubberzone 58 which contains an amine selective to hydrogen sulfide, but notselective to carbon dioxide. Again, suitable amines are available fromDOW and from BASF, and in one embodiment the amines are a promoted oractivated MDEA. Suitable amines for the second amine absorber zone fromDOW include the UCARSOL™ HS series solvents such as HS101, HS102, HS103,HS104, HS115. Therefore the carbon dioxide passes through second aminescrubber zone 58 and into line 66. The amine may be regenerated whichreleases the hydrogen sulfide into line 60. Regenerated amine is thenreused, and the hydrogen sulfide may be recycled to the deoxygenationreaction zone. Conditions for the first scrubber zone includes atemperature in the range of 30 to 60° C. The first absorber is operatedat essentially the same pressure as the reaction zone. By “essentially”it is meant that the operating pressure of the first absorber is withinabout 1034 kPa absolute (150 psia) of the operating pressure of thereaction zone. For example, the pressure of the first absorber is nomore than 1034 kPa absolute (150 psia) less than that of the reactionzone. The second amine absorber zone is operated in a pressure range offrom 138 kPa absolute (20 psia) to 241 kPa absolute (35 psia). Also, atleast the first the absorber is operated at a temperature that is atleast 1° C. higher than that of the separator. Keeping the absorberswarmer than the separator operates to maintain any light hydrocarbons inthe vapor phase and prevents the light hydrocarbons from condensing intothe absorber solvent.

It is readily understood that instead of a portion of the diesel rangecomponents in line 46 being optionally recycled in line 46 a to hot highpressure hydrogen stripper 8 optional rectification zone 23 and used asa rectification agent, a portion of naphtha/gasoline bottoms 52 isoptionally recycled to hot high pressure hydrogen stripper 8 optionalrectification zone 23 and used as a rectification agent. Similarly,instead of a portion of the diesel range components in line 46 beingoptionally recycled in line 46 a to hot high pressure hydrogen stripper8 optional rectification zone 23 and used as a rectification agent, thediesel range components in line 46 a and portion of naphtha/gasolinebottoms 52 combined to form a rectification agent stream which isoptionally recycled to hot high pressure hydrogen stripper 8 optionalrectification zone 23 and used as a rectification agent. In oneembodiment, diesel range components in line 46 may be recycled to theisomerization and selective hydrocracking zone to increase the yield ofaviation boiling point range product.

Minimizing the amount of normal paraffins that bypass the isomerizationand selective hydrocracking zone helps to meet freeze pointspecifications for many aviation fuels without having to significantlylower the quantity of aviation fuel produced. Normal paraffins thatbypass the isomerization and selective hydrocracking zone are notisomerized and the normal paraffins generally have higher freeze pointsthan the corresponding isomerized paraffins.

In another embodiment, as shown in FIG. 2, feedstock 110 of wholepyrolysis oil and triglycerides and FFA enters partial deoxygenationzone 112 along with recycle hydrogen stream 154 and optional hydrocarbonrecycle 156 where contact with a deoxygenation and hydrogenationcatalyst at deoxygenation conditions generates partially deoxygenatedstream 114. The deoxygenation zone 112 performs catalyticdecarboxylation, decarbonylation, and hydrodeoxygenation of thetriglycerides and of the oxygen polymers and single oxygenated moleculesin the pyrolysis oil by breaking the oxygen linkages, and forming waterand CO₂ from the oxygen and leaving smaller molecules as discussedabove. Hydrogenation of olefins also occur in this zone. The catalystsand conditions of partial deoxygenation zone 112 are selected so thatthe more reactive compounds are deoxygenated. The effluent of partialdeoxygenation zone is a partially deoxygenated stream 114 that hasincreased thermal stability as compared to the feed mixture oftriglycerides, FFA and pyrolysis oil.

Partially deoxygenated stream 114 is passed to a separation zone 116.Carbon oxides, possibly hydrogen sulfide, and C3 and lighter componentsare separated and removed in overhead line 120 and a partiallydeoxygenated product stream 118 is removed from separation zone 116.Separation zone 116 may comprise a separator. Depending upon whether theseparator is operated in a hot or cold mode, the water may be removed asa vapor in line 120 (hot separator mode) or as a liquid in line 122(cold separator mode). Overhead line 120 comprises a large quantity ofhydrogen and at least the carbon dioxide from the decarboxylationreaction. The carbon dioxide can be removed from the hydrogen by meanswell known in the art such as reaction with a hot carbonate solution,pressure swing absorption, etc. Also, absorption with an amine inprocesses such as described in co-pending applications U.S. Ser. No.12/193,176 and U.S. Ser. No. 12/193,196, hereby incorporated byreference, may be employed. If desired, essentially pure carbon dioxidecan be recovered by regenerating the spent absorption media. Thereforeoverhead line 120 is passed through one or more scrubbers 144 such asamine scrubbers to remove carbon dioxide in line 146 and hydrogensulfide in line 148. Depending upon the scrubber technology selectedsome portion of water may also be retained by the scrubber. The lighterhydrocarbons and gasses, possibly including a portion of water, areconducted via line 150 to steam reforming zone 152. In one embodimentthe light hydrocarbon fractions may contain hydrocarbons with six orfewer carbon atoms. After purification, hydrogen generated in steamreforming zone 152 is conducted via line 154 to combine with feedstock110 and partially deoxygenated product stream 118. The hydrogen may berecycled to combine with the feedstock as shown or may be introduceddirectly to the reaction zone where hydrogenation primarily occursand/or to any subsequent reactor beds.

The partially deoxygenated product stream 118 along with recyclehydrogen stream 154 and optional hydrocarbon recycle 156, is passed to afull hydrodeoxygenation zone 124, where the remaining oxygen is removed.Full deoxygenation zone 124 performs catalytic decarboxylation,decarbonylation, and hydrodeoxygenation of the remaining oxygencompounds that are more stable than those reacted in the first stage.Therefore, a more active catalyst and more severe process conditions areemployed in full deoxygenation zone 124 as compared to partialdeoxygenation zone 112 in order to catalyze full deoxygenation.

Full deoxygenation zone effluent 126 is introduced to phase separator128. Carbon oxides, possibly hydrogen sulfide and C3 and lightercomponents are separated and removed in line 130 and liquid hydrocarbonsare removed in line 132. Depending upon whether the separator isoperated in a hot or cold mode, the water may be removed as a vapor inline 130 (hot separator mode) or as a liquid in line 158 (cold separatormode). The overhead in line 130 comprises a large quantity of hydrogenand the carbon dioxide from the decarboxylation reaction. The carbondioxide can be removed from the hydrogen by means well known in the art,reaction with a hot carbonate solution, pressure swing absorption, etc.Also, absorption with an amine in processes such as described inco-pending applications U.S. Ser. No. 12/193,176 and U.S. Ser. No.12/193,196, hereby incorporated by reference, may be employed. Ifdesired, essentially pure carbon dioxide can be recovered byregenerating the spent absorption media. Therefore line 130 is passedthrough one or more scrubbers 144 such as amine scrubbers to removecarbon dioxide in line 146 and hydrogen sulfide in line 148. Dependingupon the scrubber technology selected some portion of water may also beretained by the scrubber. The lighter hydrocarbons and gasses, possiblyincluding a portion of water, are conducted via line 150 to steamreforming zone 152. A liquid stream containing hydrocarbons is removedfrom separator 128 in line 132 and conducted to product fractionationzone 134. Product fractionation zone 134 is operated so that the lightermaterials such as naphtha and LPG are removed in fractionation zoneoverhead stream 160. A portion of stream 160 may be optionally conductedin line 162 to the reforming zone 152. If desired, the naphtha and LPGmay be further separated into an LPG stream and a naphtha stream (notshown). Product cut 136 contains the hydrocarbons in a boiling pointrange most beneficial to meeting the gasoline specifications. Productcut 138 removes hydrocarbons in a boiling range of aviation fuel or ablending component of aviation fuel. Bottoms stream 140 removeshydrocarbons that have a boiling point at least in the diesel boilingpoint range. A portion of bottoms stream 140 may be separated andrecovered and used as fuel such as, for example, low sulfur heating oilfuel (not shown). It is likely that bottoms stream 140 may be acceptablefor use as diesel or a diesel blending component. A portion of bottomsstream 140 is optionally recycled to partial deoxygenation zone 112and/or full deoxygenation reaction zone 124. A portion of a hydrocarbonstream may also be cooled down if necessary and used as cool quenchliquid between beds of one of the deoxygenation zones, or between thefirst and the full deoxygenation zone to further control the heat ofreaction and provide quench liquid for emergencies. The recycle streammay be introduced to the inlet of one or both of the reaction zonesand/or to any subsequent beds or reactors. One benefit of thehydrocarbon recycle is to control the temperature rise across theindividual beds. However, as discussed within, the amount of hydrocarbonrecycle may be determined based upon the desired hydrogen solubility inthe reaction zone. Increasing the hydrogen solubility in the reactionmixture allows for successful operation at lower pressures, and thusreduced cost. Operating with high recycle and maintaining high levels ofhydrogen in the liquid phase helps dissipate hot spots at the catalystsurface and reduces the formation of undesirable heavy components whichlead to coking and catalyst deactivation. Fractionation zone 134 maycontain more than one fractionation column and thus the locations of thedifferent streams separated may vary from that shown in the figures.

In another embodiment as shown in FIG. 3, a pyrolysis oil feed stream210 is passed through phase separator 204 where it is separated into anaqueous phase and a pyrolysis oil non-aqueous phase. A portion or all ofthe pyrolysis oil non-aqueous phase is removed from separator 204 instream 207 which is then combined with stream 206 to form combinedstream 202. Optionally, some or all of the pyrolysis oil non-aqueousphase is removed via stream 208. Part of all of the aqueous phase isremoved from separator 204 in stream 206 which is then combined withstream 207 to form combined stream 202. Optionally, aqueous phasepyrolysis oil can be removed through line 205. Combined stream 202,which is a pyrolysis oil non-aqueous phase enriched pyrolysis oil, ismixed with a second feed stream 203 comprising triglycerides and FFAs toform combined feed 209 which passes into partial deoxygenation zone 112where partial deoxygenation occurs along with hydrogenation of reactivefunctional groups as described above. The partially deoxygenated productstream 114 passes through separator 116 where CO, CO2, H2O, and H2S areremoved. Product stream 118 passes through full deoxygenation zone 124where complete deoxygenation is catalyzed. Full deoxygenation zoneproduct stream 126 passes through separator 128 where water, CO, CO2,and H2S are removed resulting in a liquid hydrocarbon stream 132. Liquidhydrocarbon stream 132 is passed through the fractionation zone 134where it is separated into the desired streams as discussed above.

In another embodiment as shown in FIG. 4 optionally a pyrolysis oil feedstream 210 is passed through phase separator 204 where it is separatedinto an aqueous phase and a pyrolysis oil non-aqueous phase. A portionor all of pyrolysis oil non-aqueous phase is removed from separator 204in stream 207 which is then combined with stream 206 to form combinedstream 202. Optionally, some or all of the pyrolysis oil non-aqueousphase is removed via stream 208. Part of all of the aqueous phase isremoved from separator 204 in stream 206 which is then combined withstream 207 to form combined stream 202. Optionally, aqueous phasepyrolysis oil can be removed through line 205. Triglyceride and FFAstream 203 is added to combined stream 202 to form feed stream 209.Either feed stream 209 (for the embodiment using pyrolysis oilnon-aqueous phase enriched pyrolysis oil), or pyrolysis oil feed stream210 (for the embodiment using the whole pyrolysis oil) combined withTriglyceride and FFA stream 203 passes through deoxygenation zone 325where contact with one or more catalysts fully deoxygenate the feed toproduce a fully deoxygenated product stream 327. Deoxygenation zone 325can employ a multifunctional catalyst capable of deoxygenation andhydrogenation or a set of catalysts. For example, partial deoxygenationand hydrogenation can occur over the first catalyst in a first portionof zone 325 while full deoxygenation occurs in a more active catalyst ina second portion of zone 325. A stacked bed configuration may beadvantageous because a less active catalyst in an upper zone willdeoxygenate the most reactive oxygen compounds without generatingexotherms that can promote the formation of thermal coke. The fullydeoxygenated product stream 327 is fed to phase separator 128 wherewater, CO, CO2, and H2S are removed resulting in a liquid hydrocarbonstream 132. Liquid hydrocarbon stream 132 is passed through thefractionation zone 134 where it is separated into the desired streams asdiscussed above.

A portion of a hydrocarbon stream may also be cooled down if necessaryand used as cool quench liquid between beds of one of the deoxygenationzones, or between the first and the full deoxygenation zone to furthercontrol the heat of reaction and provide quench liquid for emergencies.The recycle stream may be introduced to the inlet of one or both of thereaction zones and/or to any subsequent beds or reactors. One benefit ofthe hydrocarbon recycle is to control the temperature rise across theindividual beds. However, as discussed within, the amount of hydrocarbonrecycle may be is determined based upon the desired hydrogen solubilityin the reaction zone. Increasing the hydrogen solubility in the reactionmixture allows for successful operation at lower pressures, and thusreduced cost. Operating with high recycle and maintaining high levels ofhydrogen in the liquid phase helps dissipate hot spots at the catalystsurface and reduces the formation of undesirable heavy components whichlead to coking and catalyst deactivation. The fractionation zone maycontain more than one fractionation column and thus the locations of thedifferent streams separated may vary from that shown in the figures.

In another embodiment, the pyrolysis oil feed stream is separated toremove at least a portion of the aqueous phase thereby concentrating theamount of pyrolysis oil non-aqueous phase left in the pyrolysis oil andgenerating a pyrolysis oil non-aqueous phase-enriched pyrolysis oil. Theseparation may be accomplished by passing the pyrolysis oil through aphase separator where it is separated into an aqueous phase and apyrolysis oil non-aqueous phase and removing at least a portion of theaqueous phase.

In another embodiment, both deoxygenation zones are housed in a singlereactor. The deoxygenation zones may be combined through the use of amultifunctional catalyst capable of deoxygenation and hydrogenation or aset of catalysts. Or a reactor housing two separate zones, such as astacked bed reactor, may be employed. For example, partial deoxygenationand hydrogenation can occur over the first catalyst in a first portionof a reactor, a first zone, while full deoxygenation occurs with a moreactive catalyst in a second portion the reactor, a second zone. Astacked bed configuration may be advantageous because a less activecatalyst in an upper zone will deoxygenate the most reactive oxygencompounds without generating exotherms that can promote the formation ofthermal coke.

Hydrogen is needed for the deoxygenation and hydrogenation reactionsabove, and to be effective, a sufficient quantity of hydrogen must be insolution in the deoxygenation zone to most effectively take part in thecatalytic reaction. If hydrogen is not available at the reaction site ofthe catalyst, the coke forms on the catalyst and deactivates thecatalyst. High operating pressures may be used in order to achieve adesired amount of hydrogen in solution and readily available forreaction and to avoid coking reactions on the catalyst. However, higherpressure operations are more costly to build and to operate as comparedto their lower pressure counterparts.

The desired amount of hydrogen may be kept in solution at lowerpressures by employing a large recycle of hydrocarbon. An added benefitis the control of the temperature in the deoxygenation zone(s) since thedeoxygenation reactions are exothermic reactions. However, the range ofrecycle to feedstock ratios used herein is set based on the need tocontrol the level of hydrogen in the liquid phase and therefore reducethe deactivation rate of the catalyst. The amount of recycle isdetermined not on temperature control requirements, but instead, basedupon hydrogen solubility requirements. Hydrogen has a greater solubilityin the hydrocarbon product than it does in the pyrolysis oil feedstockor the portion of the pyrolysis oil feedstock after separation. Byutilizing a large hydrocarbon recycle the solubility of hydrogen in theliquid phase in the reaction zone is greatly increased and higherpressures are not needed to increase the amount of hydrogen in solutionand avoid catalyst deactivation at low pressures. The hydrocarbonrecycle may be a portion of the stream in any of lines 132, 140, 138, or136, or any combination thereof, and the hydrocarbon recycle is directedto deoxygenation zone 112 or 325. The figure shows optional hydrocarbonrecycle 156 as a portion of diesel boiling point range component 140.However it is understood that in other embodiments portions differentstreams or combinations of stream such as the product stream 132 or anyof fractionation zone streams 138, 136, 160 may be used as thehydrocarbon recycle. Suitable volume ratios of hydrocarbon recycle topyrolysis oil feedstock is from about 2:1 to about 8:1. In anotherembodiment the ratio is in the range of about 3:1 to about 6:1 and inyet another embodiment the ratio is in the range of about 4:1 to about5:1.

Furthermore, the rate of reaction in the deoxygenation zone is increasedwith the hydrocarbon recycle resulting in a greater amount of throughputof material through the reactor in a given period of time. Loweroperating pressures provide an additional advantage in increasing thedecarboxylation reaction while reducing the hydrodeoxygenation reaction.The result is a reduction in the amount of hydrogen required to removeoxygen from the feedstock component and produce a finished product.Hydrogen can be a costly component of the feed and reduction of thehydrogen requirements is beneficial from an economic standpoint.

In another embodiment, mixtures or co-feeds of the pyrolysis oil,triglycerides and FFA and other renewable feedstocks or petroleumderived hydrocarbons may also be used as the feedstock to thedeoxygenation zone. The mixture of the pyrolysis oil and anotherrenewable feedstock or a petroleum derived hydrocarbon is selected toresult in greater hydrogen solubility. Other feedstock components whichmay be used as a co-feed component in combination with the pyrolysis oilfrom the above listed biomass materials, include spent motor oil andindustrial lubricants, used paraffin waxes, liquids derived fromgasification of coal, biomass, or natural gas followed by a downstreamliquefaction step such as Fischer-Tropsch technology; liquids derivedfrom depolymerization, thermal or chemical, of waste plastics such aspolypropylene, high density polyethylene, and low density polyethylene;and other synthetic oils generated as byproducts from petrochemical andchemical processes. One advantage of using a co-feed component is thetransformation of what has been considered to be a waste product from apetroleum based or other process into a valuable co-feed component tothe current process.

The partial deoxygenation zone is operated at a pressure from about 3.4MPa (500 psia) to about 14 MPa (3000 psia), and preferably is operatedat a pressure from about 3.4 MPa (500 psia) to about 12 MPa (1800 psia).The partial deoxygenation zone is operated at a temperature from about100° C. to 400° C. with one embodiment being from about 300° C. to about375° C. The partial deoxygenation zone is operated at a space velocityfrom about 0.1 LHSV h⁻¹ to 1.5 LHSV h⁻¹ based on the combined feedstock;this space velocity range does not include any contribution from arecycle stream. In one embodiment the space velocity is from about 0.25to about 1.0 LHSV h⁻¹. The hydrogen to liquid hydrocarbon feed ratio isat about 5000 to 20000 scf/bbl with one embodiment being from about10,000 to 15,000 scf/bbl. The catalyst in the partial deoxygenation zoneis any hydrogenation and hydrotreating catalysts well known in the artsuch as nickel or nickel/molybdenum dispersed on a high surface areasupport. Other hydrogenation catalysts include one or more noble metalcatalytic elements dispersed on a high surface area support.Non-limiting examples of noble metals include Pt and/or Pd dispersed ongamma-alumina or activated carbon. Another example includes thecatalysts disclosed in U.S. Pat. No. 6,841,085, hereby incorporated byreference.

In the full deoxygenation zone, the conditions are more severe and thecatalyst more active compared to that of the partial deoxygenation zone.The catalyst is any hydrocracking catalyst, having a hydrocrackingfunction, that is well known in the art such as nickel ornickel/molybdenum dispersed on a high surface area support. Anotherexample is a combined zeolitic and amorphous silica-alumina catalystwith a metal deposited on the catalyst. The catalyst includes at leastone metal selected from nickel (Ni), chromium (Cr), molybdenum (Mo),tungsten (W), cobalt (Co), rhodium (Rh), iridium (Ir), ruthenium (Ru),and rhenium (Re). In one embodiment, the catalyst includes a mixture ofthe metals Ni and Mo on the catalyst. The catalyst is preferably a largepore catalyst that provides sufficient pore size for allowing largermolecules into the pores for cracking to smaller molecular constituents.The metal content deposited on the catalysts used are deposited inamounts ranging from 0.1 wt. % to 20 wt. %, with specific embodimentshaving values for the metals including, but not limited to, nickel in arange from 0.5 wt. % to 10 wt. %, tungsten in a range from 5 wt. % to 20wt. %, and molybdenum in a range from 5 wt. % to 20 wt. %. The metalscan also be deposited in combinations on the catalysts with examplecombinations being Ni with W, and Ni with Mo. Zeolites used for thecatalysts include, but are not limited to, beta zeolite, Y-zeolite, MFItype zeolites, mordenite, silicalite, SM3, and faujasite. The catalystsare capable of catalyzing decarboxylation, decarbonylation and/orhydrodeoxygenation of the feedstock to remove oxygen as well ashydrogenation to saturate olefins. Cracking may also occur.Decarboxylation, decarbonylation, and hydrodeoxygenation are hereincollectively referred to as deoxygenation reactions.

The full deoxygenation zone conditions include a relatively low pressureof about 3447 kPa (500 psia) to about 13,790 kPa (2000 psia), atemperature of about 300° C. to about 500° C. and a liquid hourly spacevelocity of about 0.1 to about 3 hr⁻¹ based on fresh feed not recycle.In another embodiment the deoxygenation conditions include the samepressure of about 6890 kPa (1000 psia) to about 6895 kPa (1700 psia), atemperature of about 350° C. to about 450° C. and a liquid hourly spacevelocity of about 0.15 to about 0.40 hr⁻¹. It is envisioned and iswithin the scope of this invention that all the reactions are occurringsimultaneously within a zone.

The invention claimed is:
 1. A process for producing a fuel comprising:a) treating a first renewable feedstock comprising at least glyceridesand a second renewable feedstock comprising at least whole pyrolysis oilconcurrently in a first reaction zone by catalytically hydrogenating andcatalytically deoxygenating the glycerides and components of the wholepyrolysis oil using at least one catalyst at reaction conditions in thepresence of hydrogen to provide an effluent stream comprising hydrogen,water, carbon oxides, and hydrocarbons; and b) separating at leasthydrogen, carbon dioxide, and water, from the effluent stream andcollecting at least a portion of the remainder for use as a fuel or fuelblending component.
 2. The process of claim 1 further comprisingseparating the remainder into a gasoline boiling point range component,an aviation boiling point range component, and a diesel boiling pointrange component.
 3. The process of claim 1 further comprisingintroducing at least a portion of the hydrocarbons generated in thefirst reaction zone to a second reaction zone to contact anisomerization and selective hydrocracking catalyst at isomerization andselective hydrocracking conditions to selectively hydrocrack at least aportion of the hydrocarbons and to isomerize at least a portion of thehydrocarbons, to generate the effluent stream.
 4. The process of claim 3further comprising selectively separating, in a hot high pressurehydrogen stripper, a gaseous stream comprising at least a portion of thehydrogen, water, and carbon oxides from the hydrocarbons to generate thehydrocarbons passed to the second reaction zone.
 5. The process of claim4 further comprising recycling, to a rectification zone in the hot highpressure hydrogen stripper, a portion of the remainder.
 6. The processof claim 4 wherein the second reaction zone effluent further compriseshydrogen and at least a portion of the hydrogen is separated from theeffluent stream and recycled to the hot high pressure hydrogen stripper.7. The process of claim 1 wherein the remainder comprises hydrocarbonsin the diesel, gasoline, and aviation boiling point ranges.
 8. Theprocess of claim 1 wherein the first and second renewable feedstocks arederived from a single renewable source.
 9. The process of claim 1further comprising recycling a portion of the hydrocarbons from thefirst reaction zone back to the first reaction zone at a volume ratio ofrecycle to renewable feedstock in the range of about 2:1 to about 8:1.10. The process of claim 3 further comprising recycling at least aportion of the remainder to the second reaction zone.
 11. The process ofclaim 1 further comprising pre-treating the first renewable feedstock,the second renewable feedstock, or both in one or more pretreatmentzones at pretreatment conditions to remove at least a portion ofcontaminants in the feedstocks.
 12. The process of claim 3 wherein thefirst and second reaction zones are operated at conditions including atemperature of about 40° C. to about 400° C. and a pressure of about 689kPa absolute (100 psia) to about 13,790 kPa absolute (2000 psia); 13.The process of claim 4 wherein the hot high pressure hydrogen stripperis operated at a temperature of about 40° C. to about 300° C. and apressure of about 689 kPa absolute (100 psia) to about 13,790 kPaabsolute (2000 psia).
 14. The process of claim 4 wherein the hot highpressure hydrogen stripper is operated at a pressure that is within 1034kPa absolute (150 psia) that of the first reaction zone and the secondreaction zone is operated at a pressure at least about 345 kPa absolute(50 psia) greater than that of the first reaction zone.
 15. The processof claim 1 further comprising a third feedstock treated concurrentlywith the first and second feedstocks wherein the third feedstockcomprises a petroleum hydrocarbon feedstock.
 16. A diesel boiling pointrange fuel, an aviation boiling point range fuel, and a gasoline boilingpoint range fuel as produced by the process of claim
 1. 17. The processof claim 1 further comprising mixing one or more additives to at least aportion of the remainder.
 18. The process of claim 1 wherein thetreating of the first and the second renewable feedstocks, concurrently,in the first reaction zone by hydrogenating and deoxygenating theglycerides and components of the whole pyrolysis oil comprises: a)treating the first and second renewable feedstocks by partiallydeoxygenating the glycerides and components of the whole pyrolysis oilin a partial deoxygenation zone of the first reaction zone by contactingthe first and second feedstocks concurrently with a first deoxygenationand hydrogenation catalyst in the presence of hydrogen at deoxygenationconditions to produce a partially deoxygenated stream comprising water,gasses, light ends, and hydrocarbons; b) passing the partiallydeoxygenated stream to a separation zone to separate a water, gases, andlight ends stream from a hydrocarbon stream; and c) passing thehydrocarbon stream to a full deoxygenation zone of the first reactionzone and deoxygenating the hydrocarbon stream by contacting with asecond deoxygenation catalyst under deoxygenation conditions, togenerate the effluent stream.
 19. The process of claim 18 wherein thepartial deoxygenation zone is operated at a pressure in the range from3.4 MPa a (500 psia) to about 20.6 MPa a (3000 psia) and a temperaturein the range of about 100° C. to about 400° C.; and the fulldeoxygenation zone is operated at a pressure between about 689 kPa (100psia) to about 13.8 MPa a (2000 psia) and at a temperature of about 300°C. to about 500° C.
 20. The process of claim 18 further comprisingrecycling a portion of the remainder to the partial deoxygenation zone,the full deoxygenation zone, or both wherein the volume ratio of recycleto feed to the partial or full deoxygenation zone is in the range ofabout 2:1 to about 8:1.